JPH02500676A - screw compressor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Screw compressor The present invention provides a male rotor and a female rotor having spirally extending grooves that mesh with each other. The present invention relates to a rotary screw compressor. The rotor of this type of compressor has a shaft that supports the rotor. It is equipped with a yarn.

This special type of compressor is known. A typical example is the Swedish published patent It is disclosed in Specification No. 374946 and No. 418889.

In such a compressor, between the end face of the rotor and the rotor end wall at the high pressure end, there is A gap is present to avoid mechanical contact between the two sides. This gap is exposed to the end wall. from the exit chamber radially inward to the shaft journal and along it toward the bearing. This constitutes a leakage path for the compressed working fluid that once flows.

The rotor of this type of compressor usually has a helical groove that extends deep into the rotor and the shaft gear The radial distance between the nut and the groove bottom is small, resulting in leakage constituted by the gap. The passage will be extremely short. Therefore, the compressed working fluid is not much of an obstacle. You can easily reach the axis journal. Compressed working fluid leaks into the bearing chamber. To prevent this from happening, a shaft seal is usually provided between the bearing and the rotor body.

The object of the invention is to provide this special type of compressor with a shaft seal at the high pressure end of the compressor. The goal is to simplify the process by removing the need to do so.

According to the invention, this means that the compressor has the features specified in claim 1 in the claims. This is achieved by being prepared.

Advantageous embodiments of the invention are described in the dependent claims.

FIG. 1 is a longitudinal section through the high pressure end of the compressor.

FIG. 2 is a cross-sectional view taken along line 2-2 of FIG. 1, omitting details not necessary for the present invention. It is.

In FIG. 1, the discharge end of the compressor is illustrated. The compressor is a male rotor with five grooves. The rotor includes a rotor 2 and a female rotor 3 having six grooves. Each rotor is connected to the high pressure end. It has a shaft journal 4.5 which is pivotally supported by a dollar bearing 6.7. rotor A gap d is formed between the end face 8.9 and the wall.

As stated in the introduction, this gap d constitutes a leakage path for the compressed working fluid. , the working fluid passes from there to the shaft journal 4.5 and further to the bearing.

As can be seen in Figure 2, the rotor has a relatively shallow groove and a relatively narrow shaft journal. It is formed. Therefore, in each case, between the groove bottom and the associated shaft journal, Distance t! , and A, are long (approximately 176 mm of the rotor diameter due to the shallow grooves) A groove depth of 115 mm is formed, and the narrow shaft journal provides a groove depth of approximately 115 mm. A diameter of 1/4 is formed. The length of the leakage path is approximately 171 mm of the associated rotor diameter. It would be equivalent to 5 to 1/20.

! ! The length between the bottom and the shaft journal is the sealed gap passing through the gap between the rotor end face and the end wall. is sufficient to establish a sealing effect and significantly reduce leakage. So A satisfactory seal through this was achieved, eliminating the need for special shaft seals for each shaft journal. It disappears.

In the illustrated embodiment, a groove with many lobes is used to achieve a shallow groove depth. Although a rotor is preferred, a 5+6 lobe combination is selected. did Therefore, 5+7 and higher lobe combinations are also suitable for the compressor according to the invention. It is especially suitable for

The seal becomes more effective as the gap d between the rotor end face 8.9 and the end wall 10 becomes narrower. Ru. In order to obtain as narrow a gap as possible, the shaft journal 4.5 lies close to the end wall IO.

This increases the risk of rotor end face tilting caused by thin shaft journals. The gap can be kept narrow due to the opposing action.

Needle bearings are used as bearings 6.7, the radial dimensions of which are small. this In this way the holes in the end wall of the shaft journal can be made small and each long seam It is possible to achieve a clearance z, , Il.

International investigation report Insect 111#I’li・111-＾綽虽ELLLL＾-+1p(7、上三ετO0 2163

Claims (1)

[Claims] 1. A male rotor (2) and a female rotor having spirally extending grooves that mesh with each other (3), wherein the rotor is provided with a shaft shaft at each end thereof for pivotally supporting the rotor. The rotary screw compressor has a groove in the male rotor (2) and a groove in the female rotor (3). Their associated axial shears (4, 5) at the shallow and high-pressure end are narrow and groove bottoms. The clearance with the associated shaft journal (4, 5) is the end face (8, 9) of the rotor (2, 3). and the end wall (10) at the high pressure end is established. Rotary screw compressor, characterized by sufficient length. 2. characterized in that said radial distance is greater than 1/6 of the associated rotor diameter. The rotary screw compressor according to claim 1. 3. The shaft journals (4, 5) at the high pressure end are journalled closely against the end wall. The rotary screw compressor according to claim 1 or 2, characterized in that: 4. Bearings with small radial dimensions, preferably with shaft journals (4, 5) at the high pressure end or a needle bearing. The rotary screw compressor according to any one of the above. 5. characterized in that the shaft journals (4, 5) at the high pressure end have no shaft seals; The rotary screw compressor according to any one of claims 1 to 4.